Nature

Ecological restoration now

Sam Gandy
8th July 2020
11 min read

Humanity’s post Covid invitation - can we heal the world to heal ourselves?

The vital need for ecological restoration on a global scale

It is widely understood that we have entered the sixth mass extinction of life on this planet, due entirely to human actions on the biosphere. The publication of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) report in May of last year… considered the most comprehensive assessment of its kind… makes for grim reading. Complied by 145 expert authors from 50 countries assessing changes over the past 50 years, the assessment found that nature is declining at rates unprecedented in human history, with ecological degradation and rates of species extinctions accelerating, with over a million species now threatened with extinction.

Degradation of land and marine ecosystems is thought to undermine the well-being of 3.2 billion people, with around 20% of the planet’s vegetated surface showing declines in productivity linked to ecological degradation all over the world, with this predicted to worsen over the coming century. The restoration of 350 million hectares of degraded land between now and 2030 could generate US $9 trillion in ecosystem services and take an additional 13-26 gigatons of greenhouse gases out of the atmosphere.

In light of this, last year the United Nations declared 2021–2030 the “UN Decade on Ecosystem Restoration”, stating that global ecosystem restoration offers an unparalleled opportunity to enhance biodiversity and food and water security, create jobs and combat climate change. Ecosystem restoration is defined as the process of renewing or restoring damaged, degraded, or destroyed ecosystems and habitats by active human intervention and action to facilitate the regeneration of their ecological functionality.

Following in the wake of Coronavirus, which has forced many of us to slow down and tread more lightly, many UK citizens have had more time to connect with and appreciate nature, with one YouGov poll indicating that 70% of people would like to see nature being enhanced, with more wildlife and plant species in shared green spaces, with a desire for the latter to be less manicured, and left wilder.

Beaver standing to feed - photo credit - Gordon Muir

Ecosystem engineers as agents of ecological restoration

Ecological restoration may be achieved in several ways, varying with the habitat or ecosystem in question. Certain species wield greater power than others with regard to influencing ecosystems and the biodiversity they support. Such species are termed ecosystem engineers or keystone species. The reintroduction of these species can play a vital role in ecosystem restoration.

Beavers are viewed as perhaps the prototypical ecosystem engineer or keystone species. They are water gardeners, creating a mosaic of wetland habitat through their dam building, which in turn markedly boosts biodiversity, while also filtering sediment and fertilisers and helping buffer against both flooding and drought. They were hunted to extinction in Britain around 400 years ago, and at one point are thought to have influenced up to 30% of the British landmass. While officially designated a protected species in Scotland, they are being heavily culled, despite the option of relocation to areas where they aren’t likely to come into conflict with humans. With appropriate management, beavers could act as powerful agents of ecological restoration, and the potential benefits of a well-managed beaver population far exceed any potential drawbacks.

The reintroduction of an apex predator is an example of a top-down approach to ecosystem restoration, yielding a trophic cascade. This is an ecological process that starts at the top of the food chain, extending downwards. There has been talk of reintroducing lynx to some forested parts of Scotland. Lynx were hunted to extinction in Britain sometime after the Middle Ages. Following their absence, along with the loss of other large predators from the landscape, deer populations have ballooned, and overgrazing in Scotland inflicts great ecological damage, preventing natural regeneration of woodland in many areas.

A Eurasian lynx in the Jura Mountains, Switzerland - photo credit - Laurent Geslin

The trophic cascade catalysed by the reintroduction of an apex predator is illustrated powerfully by the reintroduction of wolves to Yellowstone National Park. Following an absence of 70 years, 14 grey wolves were reintroduced in 1995. Their presence immediately began to exert a number of ecological effects, among them their impacts on grazers such as elk, with previous human attempts at control proving ineffective. Wolves helped keep a lid on elk populations, which had been very high, pushing the limits of Yellowstone’s carrying capacity. More important than control of elk populations was the changes to the elk’s behaviour, with research conducted on lynx in Europe, in addition to other predators elsewhere, revealing this predator-induced behavioural change applies in many other contexts.

With wolves back, elk tended to move around a lot more, and so spread their grazing pressure out over a much greater area. They would also avoid areas they might be cornered, such as the valleys and gorges. In the wake of this, there was a rapid regeneration of different tree species, in turn providing more habitat for songbirds, and also food and habitat for beavers. Ecological engineering by beavers provided habitat for many other species, and even affected the physical geography of rivers they recolonised.

https://www.youtube.com/watch?v=oSBL7Gk_9QU

While reintroducing apex predators or ecosystem engineers constitutes a top-down approach to ecological restoration, bottom-up methods are also employed. Britain has the lowest woodland cover of all of Europe, and there are a number of reforestation projects active in various different regions. Heavy grazing pressure from deer, and a lack of tree seed dispersers such as red squirrels in many areas means that a helping human hand can help get new forests established more quickly. There are a number of exciting reforestation projects in various parts of Britain such as the Northern Forest in northern England, The Heart of England Forest in the Midlands, Dundreggan Forest in southern Scotland, and plans for a forest stretching the length of Wales.

Beaver wetland Bamff estate - photo credit - Scottish Wild Beaver Group

Learning to work with nature rather than against her

Working with nature, rather than seeking to tame and control her, will be important for the ecological challenges we may face in the wake of climate change and issues like sea level rise which stem from this. This approach sits in stark contrast to how Britain has been managed over the centuries, the landscape being heavily manipulated and manicured. Wallasea Island, lying near the mouth of the Thames, is the largest coastal habitat restoration site in Europe. In 2006, a pioneering £7.5 million project converted former farmland into mud flats, salt marsh and saline lagoons by bulldozing 300m of sea defence wall, resulting in the sea retaking 115 hectares of land. This was followed by a further expansion of work in 2012, opening up Wallasea’s remaining sea walls.

When the sea reclaims this land, each successive tide deposits silt. In turn, a community of salt marsh plants will colonise this, trapping yet more silt. The level of the mud flats and salt marshes will rise with the rising sea level, and by keeping pace with it, offer a dynamic form of flood defence, buffering the coast from flooding and erosion, while providing habitat for a number of rare species, and sequestering vast amounts of carbon. Compare this to the Thames Barrier, which cost over half a billion pounds to construct, and is already half way through its operational lifespan, with the standard of protection it provides predicted to gradually decline after 2030.

https://www.youtube.com/watch?v=YBLZmwlPa8A&t=18s

“Hands off” ecological restoration - AKA - Rewilding

In other instances, human input to facilitate ecological restoration may be minimal and “hand’s off”, with this approach sometimes being labelled “rewilding”. This is about stepping back and allowing natural ecological processes to occur, and giving wildlife the space to do as it will. Knepp Estate can be considered a flagship rewilding project in the UK, comprising 3,500 acres of degraded farmland in West Sussex that was once intensively farmed, but struggled to turn a profit.

Knepp before & after

It was left to nature 20 years ago, although one human intervention was the introduction of different grazing animals, ancient breeds such as longhorn cattle, Tamworth pigs, and several species of deer, the former species acting as proxies for ancestral wild species such as aurochs and boar. These species inject ecological dynamism into the Knepp landscape through browsing on vegetation, transporting seeds and turning over soil, benefitting many species in the process, while yielding a reliable source of income.

In the past two decades, Knepp has transformed into a very rich, wild landscape, supporting rare species such as nightingales, turtle doves, barbastelle bats, purple emperor butterflies, and supporting the first reintroduced, breeding white storks in Britain. The success of Knepp, described in the project’s co-instigator Isabella Tree’s book Wilding, has been a huge source of inspiration to others, and plans for many other rewilding projects on various scales have followed in its wake.

https://www.youtube.com/watch?v=ikNVLbRKI_8&feature=emb_title

Ecological restoration - actions an individual can undertake

“The one who plants trees, knowing that he will never sit in their shade, has at least started to understand the meaning of life.”

- Rabindranath Tagore

Ecological restoration need not occur on the level of the landscape or ecosystem – localised efforts by individuals can all add up. The land taken up by gardens in the UK exceeds that of all of our national nature reserves combined. The UK is considered one of the most nature-depleted parts of the world. Given the importance of our connection to nature to our mental health and well-being, enhancing our native biodiversity through ecological restoration transcends ecological importance, and has major psychological implications which should not be overlooked.

We have lost 97% of our wildflower meadows since the Second World War, with serious implications for many different species such as pollinating insects like bees and butterflies. Sowing a wildflower meadow…on whatever scale one can, is a very positive step one can undertake for British wildlife. Using locally sourced UK provenance seed allows one to grow species best adapted to local conditions, while helping conserve species of wildflowers local to one’s region. Although setting up a meadow may be labour intensive initially, once established they are very low maintenance, and one will be thanked for their efforts with a meadow awash with colour and buzzing with life. It is also a good idea to leave a corner of the garden to go wild, and let nature do its thing…an approach that will sit well with the more laid back gardener. If one lacks a garden, even a window box or a few plant pots of wildflowers on a windowsill can contribute to local ecosystems.

What does your garden say about you?

Tree planting is another positive action we all can take. Our native trees support a vast array of species, none more than the oak, which supports more life than any other tree species in the UK. Up to 2,300 species are associated with oak, with 326 species completely dependent on it. Oak is a keystone species, on the decline in the UK and much of the world where they occur. Acorns can be harvested in autumn, planted in a pot of compost, (covered with 2-3cm of compost), and kept outside, or somewhere cool out of the direct sun. In spring, once the acorns have sprouted, water them once or twice a week, and plant in the ground after 1-2 years of growth.

Another positive thing to do is to dig a pond. The UK has lost 90% of its wetland habitats in the last century, with ponds becoming increasingly scarce in the British landscape. Ponds are incredible havens for all manner of wildlife, and making space for one is one of the most positive actions one can undertake for boosting biodiversity on a local scale.

In addition to these actions, a number of great organisations are helping facilitate ecological restoration work (linked in the Resources section), worthy of support through volunteering or finances. Heal is an organisation spearheading a novel, community led approach to rewilding, seeking public donations to buy land in strategic locations in the English lowlands and rewild it, for the benefit of wildlife and people.

Conserving existing ecosystems alone is not enough, and proactive restoration of human-degraded ecosystems is essential if we hope to have a future on this planet worth striving for. We are a species of immensely powerful ecosystem engineers…forearmed with the right intent and appropriate knowledge, and by learning to work with nature rather than against it, our potential in restoring Earth’s ecosystems is almost limitless. In the words of a group of ecopsychologists concluding a conference almost 30 years ago: “if the self is expanded to include the natural world, behaviour leading to destruction of the world will be experienced as self-destruction.” If this holds true, then surely the inverse applies…by restoring the planet’s ecosystems of which we are a part, by extension do we restore ourselves?